Cleaning composition



Patented Nov. 27. 1951 CLEANING COM No Drawing.v Application-June); 19.47; Serial No. 752568 I This invention. relates to: improved: cleanin compositions and" particularly to: new:-: metal cleaning and-:drycleaning compositions containing;. a chlorinated hydrocarbon; solvent;v a. detergent and water, ..tlie1 finished composition being in; sub-emulsion form; as: hereinafter; defined and described.

Inthe art oficleaning: metalssby the use of a solvent. and also. in therartxrelating. to thedrycleaning; of clothes; withiao solvent it. has been thoughtfor. many yearszthat it was: necessary to.avoid.;the presence: oft/tater;v In the..:case of metal.cleaning the-presenceiotwater in itsusual form in; such solvents: leadszto negative: cleaning andito -undesirable decomposition reactions, particularly where the solventsisa.chlorinatedhydrocarbon.=. There is; also; a:. danger; of. corrosion' of the metal inusing; such. compositions in. the presenceof: water. In. the case of. liquid dry-cleaning compositions, the presence of water in its usual form produces undesirable. shrinkage of 'the'material being cleaned; Prior attempts to incorporate water into cleaning compositions containing" such" solvents have therefore been directed to the productionofvarious soaps. containing 'ch'lorinated hydrocarbon compounds and also to moreorr'less turbid; emulsions containing soaprandi"atsolventi'such;asrarehlorinated hydrocarbon. For a number of reasons compositions of the soap type andiof the turbid emulsion type have. notrbeen satisfactory and Wetherefore do not intend to include such compositions within the scope. of the presentinvention which is directed to sub-emulsion cleaning compositions and-ctheir use.

We have-found that the difficulties of the prior artiare avoidedand a greatly--improved=- cleaning operation:- is obtained-both on metals and on clothes and the like-when water and a detergent are incorporated in a chlorinated hydrocarbon compositionrin-whatwehave in this specification termed as a-.sub-emu1sion" characterized by a clear liquidappearancein. the final form and lacking any visible? appearance" of turbidity, or of particle suspension. The sub-emulsion ofthe present invention is obtained by incorporating water into a chlorinated hydrocarbon solvent with the aid of a suitable coupler. This constitutes the basic sub-emulsion cleaning composition of the present invention. It may be necessary to add a detergent if the coupler is not a detergent and where this is done a detergent soluble in the basic sub-emulsion is selected or a suitable coupler is used for coupling the detergent into the sub-emulsion, thereby preserving: the; sub-emulsion form; However; it is possible tdselectta solvent-water coupler having detergent properties and where this is done; the addition of*a second detergent is not-necessary. The resulting cleaning composition is a. perfectly clear;easilyrfiowingrliquid and appears to derive its-superior cleaning qualities; in: part at: least, from: the? nature: of the: interface between. the

'chlorinatedthydrocarboni and the water and this interface isionei. of: theelements:- of our subem-ulsion'. As specificzexamplesiwe have found the following to be. of particulanivalue;

Example 1 .Trichlorethylene (stabilized) cc.;, Tr-iethanolamineroleate L "grams" 2 Monoethanolamine" oleate; do" 6 Sodium oleate gram; 1 Water cc v 11 The above ingredients are mixedjby, firstdissolving the triethanolamine oleate. and the monoethanolamine ol'eate. in the. trichlorethylene. The sodium oleate. is. then. dissolved inthe ,water and thissolutionismixed' with vigorous agitation. with. the. previously prepared. trichlorethylene. solution until .a sub.-emulsion..form is reached... The. formation of-the.sub.-emulsion may be accelerated; by. the. use of. heat. The final-liquidLsubl-emulsionis clear, has. a yellowisheorange colonhas. a specificgravityof 1.38

andftiarnson.agitation... Suchioamingdecreases as.the.compositionisiused andis not objectionable. For. most. metals the final sub-emulsion is..non-corrosi-ve,when. properly. used as a cleaning, composition...

I Example 2' 'Ilrichlorethylene. (stabilized) "gale- 45 ,Oleic. acid lb' 27 Triethanolamine. lb; 2.6 Monoethanolaminelb 4.0 sodiunnh-ydroxidegnun oz 7.9 .Water' "gal". 5

In the above examples the triethanolamine oleate serves primarily as a coupler for the oleic acid soap and the trichlorethylene. The monoethanolamine oleate serves primarily as a coupler for the water and the trichlorethylene, but it also has valuable cleaning characteristics. In this connection we have found that monoethanolamine oleate is far superior to triethanolamine oleate in producing and maintaining the subemulsion of this invention. This we believe is due in part to the fact that this compound has a polar group at one end of its molecular structure and a non-polar group at the other end. Its detergent properties are such that it is possible to omit the oleic acid, the sodium hydroxide and the triethanolamine from the above composition leaving the monoethanolamine oleate to act as a coupler and a detergent. The composition so attained comprises 45 gallons trichlorethylene, 5 gallons water, and 22 pounds monoethanolamine oleate, 4 pounds monoethanolamine combining with approximately 18 pounds of oleic acid to produce '22 pounds of monoethanolamine oleate. Where this is done thecleaning composition consists of a chlorinated hydrocarbon solvent, water and a coupler having detergent properties. The relative amount of water is limited to the amount which can be maintained in the composition in sub-emulsion form, herein defined as optically clear, non-turbid liquid.

We have found that the cleaning efficiency of the above compositions is far superior to that of any of the ingredients separately or to the cleaning efficiency of the same ingredients combined in other physical compositions such as pastes or turbid emulsions where the composition is not in sub-emulsion form. For instance,

'where soap is added to the usual emulsion there is no outstanding improvement in cleaning whereas soap added to our sub-emulsion in proper amount results in greatly improved cleaning. In

the cleaning of clothes and the like the removal of water soluble stains is greatly enhanced and in the metal cleaning .field the removal of smut and the like is greatly improved. This latter action probably results from the sub-emulsion interface. In this connection we have found that there is a limiting amount of water which can be used depending on the concentration of soap present. For instance we have found that the maximum amounts of water for the formation of a sub-emulsion where triethanolamine oleate is present in the composition increase with the soap concentration. Where only monoethanolamine oleate is present, significantly larger and that other well known soaps may be substituted for the sodium oleate. We have also found that sodium abietate and cyclic hydroxy compounds such as cresol and cyclohexanol make satisfactory couplers in the composition of our invention.

It'will be noted that the chlorinated hydrocarbon used in the above example, namely trichlorethylene, is designated as stabilized. Such stabilization is particularly desirable where the finished composition is to be used in vapor degreasing operations for the cleaning of metals and may be accomplished by the addition of small amounts of known stabilizers such as pyridine or triethylamine as described in U. S. Patent Number 2,096,735. Where other chlorinated hydrocarbons are used in producing the sub-emulsions referred to it may be desirable to use other stabilizers as described in the patent referred to above.

The term sub-emulsion as used throughout this specification and the appendedclaim is intended to define a composition containing a chlorinated hydrocarbon to which water has been coupled in an amount which results in a perfectly clear, non-turbid, easily flowing liquid. In some cases such sub-emulsions may be colored but even where colored there is an absence of visible particles or turbidity. In forming the sub-emulsion of the present invention it is first necessary to use a highly efiicient coupler for the solvent and the water. If the coupling agent is not a detergent, it is then necessary to include a detergent in the finished sub-emulsion and this detergent must either be soluble in the subemulsion or must be coupled into it by means of a suitable coupling agent.

Having thus described our invention, we claim:

An optically clear, non-turbid, liquid, cleaning composition comprising the following ingredients in substantially the proportions stated:

Trichlorethylene cc Triethanolamine oleate "grams" 2 Monoethanolamine oleate do 6 Sodium oleate gram 1 Water oc 11 JOHN HENRY SECRIST. WILBUR HERBERT PETERING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Emulsions Booklet of Carbide & Carbon Chem.

Corp., N. Y. (1930), pages 21, 2'2 and 23. 

